why at all you people want todownload the driver for micromax a 50 to use it as modem?
you can use it as modem (wifi device ) by using it as wifi hotspot the feature of this mobile , to connect to laptop and use it as interne modem,provided the laptop does have wifi.
go to settings
wireless and network
tethering and portable hotspot and tick portable wifi hotspot
you can configure your hotspot easily
you can also make this network as open or password protected as per your wish.
i hope now you can use your micromax a 50 ninja as a superfone .